A. Technical Field
The present invention relates to DC-DC buck voltage circuits, and particularly, to systems, devices, and methods of suppressing transient load responses in DC-DC buck voltage converters.
B. Background of the Invention
Buck or step-down DC-DC converters efficiently convert a high input DC voltage into a specified lower output DC voltage at a higher current. Buck converters are widely used in processor and power applications for consumer electronic equipment, such as desktop and portable computers; in communications equipment, such as handheld battery powered devices; in industrial applications; and in automotive applications. Buck converters often require exceptional output voltage accuracy, a reduced transient load response, and fast output voltage programming. Transient load requirements are important in low-voltage applications which are subject to fast changing load conditions or require frequent transitions between output voltage settings during operation. High-speed, high-accuracy system loads include central processing units, baseband, application and graphics processors, as well as power amplifiers. Slew rate and efficiency are important in dynamic voltage scaling and power amplifier applications.
The inductance of a DC-DC buck converter is sized to store adequate magnetic energy and keep output current and voltage ripple at reasonably low values. However, the transient output response to fast changes in system voltage and load current is limited by the current slew rate of the inductor. Additionally, prior art DC-DC buck converters which allow large output slew rate, suffer from low operating efficiency. Therefore, a need exists to overcome the deficiencies and inadequacies of the prior art.